Systems and methods for collection and detection of particulates in the air

ABSTRACT

Embodiments include systems and methods for collection and identification of particulates in the air. In one embodiment, two different path ways are provided from a single adjustable inlet: one for collection and one for detection. A removable insert positionable within a collection tube enables a user to switch between the collection mode and the detection mode. This embodiment captures both the physical mechanisms of switching the air flow paths as well as sequencing of controls and valves and regulation or changing the air flow rate in the different modes of operation. This and other embodiments are disclosed herein.

PRIORITY

This application claims priority of U.S. Provisional Application No.60/964,983 filed Aug. 16, 2007.

FIELD

The present invention is in the field, of testing of air for biological,chemical, or nuclear particulates.

BACKGROUND

Walled Cyclones (WC) are mechanical apparatus utilized for thecollection of aerosol particles for detection of trace levels of certainbiological, explosive, chemical and nuclear materials. The principle ofoperation is to separate particulates present in the air based on sizeby taking advantage of the trajectory and flow dynamics of submicronparticles as compared to macroscopic particles as the particles enter arotational vortex in a pipe. The larger particles are acted on byinertial forces that push and separate the larger particulate to theinner wall of the cyclone while the smaller air gas molecules will beexhausted through the center of the pipe, exhausted out via a blower,fan or other air moving device. The inner surface of the cyclone iswetted, coated or consists of a material conducive to capturingparticulates. Its surface is conditioned for the purpose of transportingor flushing the particulates into concentrated samples to be evaluatedby biological, chemical, explosive or nuclear sensors, detectors, andidentification apparatus.

FIG. 1 shows the basic architecture of a collection mechanism. The mainbody 102 is a pipe. The body is a molded or machined part that forms theinterior and exterior surfaces of the cyclone. Within body 102 is avortex finder 104. The vortex finder is a cone shaped protrusion at thebottom of inlet tube 106 that enhances the creation of a vortex in thecyclone body when air is flowing. An inlet tube 106 allows for inlet ofair. The inlet tube provides a contoured interior surface that directsair flow from the entrance located on the upper portion into the cyclonebody. An opening in body 102 allows the air to flow into the collectiontube of body 102 through the opening. A wetting port 108 inserts aliquid that wets the air impaction region or cyclone body below the airinlet within body wall 102. In the wetting port a liquid may be injectedinto the cyclone for formation of a wetted surface along the cyclonewall for particulate collection. Air flows in the interior of the body102 to an air outlet 110 where it is exhausted. The air outlet isinterfaced to a blower or some other air suction device that generatesthe negative pressure that induces flow in the cyclone. While the airflows toward the exhaust, particulates flow along the wetted interiorsurface of body 102 toward a collection port 112. The particulates arecollected at the collection port for future transport to sensors,detection devices and identifiers.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the invention will become apparent upon reading the followingdetailed description and upon reference to the accompanying drawings inwhich like references may indicate similar elements:

FIG. 1 depicts a basic wall cyclone apparatus

FIG. 2 depicts an embodiment for switching between a collection mode anda detection mode.

FIGS. 3A, B, and C depict an insert positionable within the collectiontube.

FIGS. 3D and 3E depicts depict an insert wrapped with a heater elementand insulation.

FIGS. 4A and 4B depict an embodiment for switching between a collectionmode and a detection mode.

FIGS. 5A and 5B depict an embodiment for switching between a collectionmode and a detection mode.

FIG. 6 depicts an embodiment with the inlet tube at an obtuse angle tothe collection tube.

FIG. 7 depicts a wetting port.

FIGS. 8A and 8B depict an embodiment for switching between a collectionmode and a detection mode.

FIGS. 9A and 9B depict an embodiment with a diaphragm to form a smoothlytransitioning aperture between the air inlet and the collection tube.

FIGS. 10A, B and C depict an embodiment with a diaphragm to form asmoothly transitioning aperture between the air inlet and the collectiontube.

FIGS. 11A and B depict an embodiment with an aperture that may be variedin size by rotation of the collection insert.

FIGS. 12A and B depict an embodiment with multiple air inlets.

FIG. 13 depicts a block diagram for adjusting airflow through the devicein response to particle size.

FIG. 14 depicts various positions and sizes of a cap over the air inlet.

DETAILED DESCRIPTION OF EMBODIMENTS

The following is a detailed description of embodiments of the inventiondepicted in the accompanying drawings. The embodiments are in suchdetail as to clearly communicate the invention. However, the amount ofdetail offered is not intended to limit the anticipated variations ofembodiments; but, on the contrary, the intention is to cover allmodifications, equivalents, and alternatives falling within the spiritand scope of the present invention as defined by the appended claims.The detailed descriptions below are designed to make such embodimentsobvious to a person of ordinary skill in the art.

Embodiments include systems and methods for collection andidentification of particulates in the air. In one embodiment, twodifferent path ways are provided: one for collection and one fordetection. A removable collection insert positionable within acollection tube enables a user to switch between the collection mode andthe detection mode. This embodiment captures both the physicalmechanisms of switching the air flow paths as well as sequencing ofcontrols and valves and regulation or changing the air flow rate in thedifferent modes of operation. This and other embodiments are discussedherein.

FIG. 2 shows an embodiment for detection and/or collection ofparticulates from the air by a collection body 202. Air from theatmosphere flows inward through a collector inlet 206. Collector inlettube 206 exhibits an interior surface that guides air into a collectioninsert 214 through an opening 226 such as a hole or slot that enablesair to flow into collection insert 214. The device 200 is capable ofoperating in two modes. One mode is collection and another mode isdetection. FIG. 2 shows operation in the detection mode. In thedetection mode, air flow is through slot 226 and through detector inlet224 into path B, through a concentrator 216, through detector 222through a valve 218 and exhausting through a blower 220. Concentrator216 receives the air from detector inlet 224 and forms it into twostreams. One stream has larger particles and one stream has smallerparticles. Detector 222 may comprise a laser optical system, aspectrometer, and/or or light, chemical or biological technologies thatpermit particles to pass through to be observed, quantified anddiscriminated. In the detection mode, valve 218 is positioned to allowair to pass from path B through the blower 220. The air flow rate can bevaried to match the correct air flow for the detection device.

Thus, in the detection mode, air flows through a detector. In acollection mode, detector inlet 224 is closed. Air flows from collectorinlet tube 206 through slot 226 into the interior of collection insert214, passing through path A through valve 218 out through blower 220.Valve 218 may be an electro-mechanical device that in the detection modeallows air to pass from path B to blower 220, and in the collection modeallows air to pass from path A to blower 220. While air is passingthrough path A, particulates settle upon the wet walls of collectioninsert 214 and travel down the length of collection insert 214 toward acollection point near the end nearest the blower.

FIG. 3A shows a view of the collection insert 314 to be inserted into aninterior cylinder (collection tube) of collection body 302. When thecollection insert 314 is fully inserted and aligned, a slot 326 alignswith slot 226 at an end of a collection inlet tube 306. In oneembodiment, another slot is in collection insert 314 that allows air toflow through to detector inlet 224. This occurs in the detection mode.

In one embodiment, a way to switch between the collection mode and thedetection mode is to rotate collection insert 314. FIG. 3B shows a crosssectional view of the collection insert 314 for this embodiment.Collection insert 314 has three slots 326, 330 and 332 cut out of thewall. The length of each slot might be, for example, ⅛ of the totallength of the collection insert. The length of the slots may beoptimized through experimentation. Persons of skill in the art willreadily recognize that instead of a slot, a hole may be employed orother opening of some shape. Two of the slots 326 and 330 are onopposite sides so that aligning one of them with slot 226 of the inlet306, causes the slot on the opposite side to align with detector inlet224. This places the device into the detection mode. When the third slot332 in the wall of collection insert 314 is aligned with slot 226 of theinlet 306, the wall on the opposite side of slot 332 blocks the detectorinlet 224. This places the device in the collection mode.

Another way to switch between collection mode and detection mode is totranslate collection insert 314. In an embodiment shown in FIG. 3C,collection insert 314 is partially inserted into the collection tube ofbody 302 in a collection mode, and is fully inserted into the collectiontube of body 302 in a detection mode. In a collection mode, collectioninsert 314 is only partially inserted so that a slot 334 in the wall ofcollection insert 314 lines up with slot 328 of collection inlet tube306. On the opposite side of slot 334 is the wall of the collectioninsert 314 which blocks inlet to detector inlet 224. In this way, airflows through path A. Not shown in FIG. 3C is a vortex finder mountednear the end of collection insert 314. This helps to create a centralvortex where particulates are pulled outward toward the interior wall ofcollection insert 314 and interior wall of body 302. In a detectionmode, collection insert 314 is fully inserted so that slot 326 alignswith slot 328 and a slot 330 in collection insert 314 aligns with inlet224. In this way, air flows through path B.

FIG. 3D shows a collection insert 314 wrapped by a heater 360 and thenwrapped by insulation 362. The heater 360 focuses heat onto thecollection insert where there is particle impaction. The insulation 362avoids wasteful heating of the cyclone body. One desires the liquid inthe collector to remain above freezing when the air entering thecollector is cold. Wrapping collection insert 314 by heater 360 enablesefficient localized heating. Prior art heating mechanisms discloseheating a substantial portion of the cyclone body, resulting in wastedenergy. Embodiments that provide localized heating of the collectioninsert avoids this wasted energy.

FIG. 4A shows an embodiment with a vortex finder insert 415. The deviceis shown in the detection mode. In the detection mode, a path C iscreated in vortex finder insert 415. Path C is shown as a slant path butcould also be a direct vertical path. To place the device in thedetection mode, therefore, one need only position vortex finder insert415 so that path C aligns with air inlet 406 and path B to allow theinlet air to pass through path C into path B through concentrator 416through detector 422 through valve 418 and then out through blower 420.Concentrator 416 is positioned in the detection path below the air inletand not in the air inlet, in contrast to some prior art detectors. FIG.4B shows the device in the collection mode. Vortex finder insert 415 ispositioned so that the vortex finder 430 is positioned just below theopening 426 to allow inlet air to flow into path A through valve 418 andout through blower 420. Note the O-ring 432 that provides asubstantially water tight boundary between the two paths. Recall thatliquid is sprayed into mix with the air flowing into air inlet 406. Thevortex finder creates a vortex which causes particulate matter andliquid to collect on the interior wall of the body in path A. Theliquid, with the particulate matter, flows in the direction of air flowalong path A on the interior wall. The liquid reaches a collection port(not shown) positioned near valve 418 where the liquid with theparticulate matter is collected.

FIG. 5A shows an embodiment with a collection insert 514 and a vortexfinder insert 515. Vortex finder insert 515 inserts into the interior ofcollection insert 515. Collection insert 514 inserts into the collectiontube of the body. FIG. 5A shows the device in the collection mode. Airflows from air inlet 506 through an opening 526 into path A moving pastvortex finder 530 through valve 518 out through blower 520. Liquid withparticulates flow along the interior of collection insert 515 toward acollection port (not shown) near valve 518. FIG. 5B shows the device inthe detection mode. Air flows from inlet 506 through opening 526 throughopening 524 into path B through concentrator 416 through detector 522through valve 518 out through blower 520.

Traditionally cyclones are fabricated in single piece assemblies out ofa uniform metallic material such as aluminum, stainless steel orplastic. In some embodiments, as described herein, fabrication of a wallcyclone assembly consists of a multiple part assembly. The assemblyincludes a molded, machined or rapid prototyped air inlet, a cycloneexterior body that forms a collection tube there within and that mateswith a collection insert that forms the interior walls of the cyclonewhere particulate collection occurs. The collection insert allows thecritical surfaces and surface finish for the impaction regions of thewall cyclone to be fabricated separately from the less critical andlower tolerance, parts of the assembly. The collection insert alsopermits the selection and tailoring of the material utilized forconstruction of the surfaces at the impaction region and those leadingup to the collection port.

Separating the insert from the rest of the cyclone assembly permits asignificant reduction in fabrication costs through a two stepfabrication process: one for higher tolerance internal surfaces and asecond for low tolerance exterior and aerodynamic inlet surfaces. Thus,one embodiment is a plastic molded part that may be mated with ametallic stainless steel or other metallic or plastic materialsconducive to particle and living biological organisms transport thattakes place in the insert. The insert can be made so that it is pressfit into a through bore in the cyclone body. This press fit allows thecollection insert to be removable from the side of the cyclone bodyopposite to the air outlet. Typically cyclonic collector interiorsurfaces should be cleaned to remove fibers and/or particulate buildupthat can occur on the walls of the interior surfaces of the cyclone.During this servicing process it is desirable to observe and inspect thesurfaces preceding the collection port for wear. Removability of theinsert enables the insert and the surfaces where the liquid is collectedto be easily inspected and serviced.

Thus, one embodiment is an air tester for testing for the presence ofbiological, chemical or nuclear particulates in the air. The embodimentcomprises an air inlet to receive air and to channel it through a firstopening in a wall of a collection tube. The embodiment further comprisesa collection tube with a removable insert to collect liquid andparticulates on the interior walls of the insert. The removable insertis positionable to align a first opening in a wall of the insert withthe first opening in a wall of the collection tube to allow air to passthrough the aligned openings. The air tester may further comprise, in awall of the collection tube, a second opening to a detection path; and,in a wall of the insert, a second opening that, in a detection mode,aligns with the second opening in the wall of the collection tube whenthe first opening in the wall of the collection tube is aligned with thefirst opening in the wall of the insert, thus allowing air to passthrough the insert to the detection path.

The embodiment may further comprise, in a wall of the insert, a thirdopening that can, in a collection mode, align with the first opening inthe wall of the collection tube when the second openings are notaligned, to allow air to pass into and through the collection tube whileair is sealed off to the detection path. In one embodiment, the insertrotates to a first position of alignment for the collection mode androtates into a second position of alignment for the detection mode. Inanother embodiment, the insert translates to a first position ofalignment for the collection mode and translates into a second positionof alignment for the detection mode.

Another embodiment is a switchable air flow device for use in a detectorof biological, chemical or nuclear particulates in the air. Theembodiment comprises an air inlet connecting to a collection tube. Thecollection tube provides one path for air to flow for collection. Adetection path provides a second path for air to flow for detection. Theembodiment comprises an insert that is positionable in the collectiontube. The insert has openings that can align with openings in thecollection tube. In a first position, the insert allows air to flow fromthe air inlet through the insert to the detection path. In a secondposition, the insert allows air to flow from the air inlet to thecollection tube while blocking the detection path when the insert is ina second position. The insert may also comprise a vortex finderpositioned in proximity to the air inlet when the device in the secondposition. In one embodiment, the insert is positionable from the firstposition to the second position by rotation of the insert. In anotherembodiment, the insert is positionable from the first position to thesecond position by translation of the insert.

Illustrations of embodiments discussed heretofore show the air inletbeing a tube that makes right angles with the direction (main axis) ofthe interior pipe forming path A (the collection tube). FIG. 6 shows analternative embodiment wherein the air inlet path 606 forms an obtuseangle with the collection tube. Note that the air inlet tube maycomprise interior walls that are shaped to optimize air flow into thedevice. Having the air inlet tube 606 make an obtuse angle with thecollection tube reduces the pressure drop across opening 626. Thisallows use of a lower power blower and/or increased air flow rate. Thisconfiguration of the air inlet tube 606, making an obtuse angle with thecollection tube, may be integrated into the devices of FIGS. 2, 3, 4 and5 or other embodiments. Thus, in some embodiments, the air inlet is atan obtuse angle to a main axis of the collection tube. This also permitsan adjustment of the size of particulate collected. So, by adjusting theangle, the size distribution of particles collected can be altered.

Not shown in FIGS. 2 through 6 is a wetting port in the wall of the airinlet 206, 306, 406, 506, 606. The wetting port allows for introductionof a liquid spray into the air inlet. In many applications, the liquidis water. In some applications, the liquid may be a solution comprisingwater and some chemical. FIG. 7 shows a wetting port 700 in a wall 706of an air inlet. Passing through a first hole 752 in wall 706 is an airinjector 754. Air injector 754 is a tube that passes air under pressurethrough injector 754 into the interior of the air inlet. Passing througha second hole 756 in wall 706 is a liquid injector 758. Liquid injector758 is a tube that passes liquid under pressure through injector 758.The end of liquid injector 758 inserts into the interior of air injector754. The air streaming through air injector 754 impacts the liquidflowing out of liquid injector 758 to cause a spray that exits airinjector 754 and mixes with the air in the inlet. In past constructionsof a wetting port, the air injector and the liquid injector are separateun-joined parts that must be placed in close proximity and in carefulalignment. Joining these two parts together as shown in FIG. 7eliminates this troublesome alignment problem. Thus, some embodimentscomprise a wetting port comprising an air injector with an interior anda liquid injector; wherein an end of the liquid injector is insertedinto the interior of the air injector.

FIG. 8A and FIG. 8B show another embodiment of a cyclonecollector/detector. In this embodiment, air inlet 806 is movable withrespect to the cyclone body 802. In the position of FIG. 8A, the deviceoperates in the detection mode. Air with particulates flow through airinlet 806 through aperture 825 through aperture 827 into air flow pathB. The device is switchable to the collection mode of operation bymoving air inlet 806 to a second position, as shown in FIG. B, so thatthe air inlet aligns with a third aperture 826 allowing air to flowthrough an aperture in the wall of collection insert 814. Air flowsthrough aperture 826, past vortex finder insert 815 into air flow pathA. In this embodiment, collection insert 814 and vortex finder insert815 are removable for cleaning, inspection and servicing.

Thus, some embodiments comprise a collection tube providing a collectionpath and a detection tube providing a detection path with: an air inletpositionable with respect to the collection tube; wherein, in a firstposition, the air inlet aligns with apertures that allow air to flowthrough a detection path; and wherein, in a second position, the airinlet aligns with an aperture to allow air to flow through a collectionpath. An embodiment may further comprise a removable collection insertwith a pair of apertures to allow air to flow through to the detectionpath and a third aperture to allow air to flow into the collection pathwhile the detection path is blocked from the air inlet. An embodimentmay further comprise a heater disposed about the collection insert toheat the collection insert. An embodiment may combine one, some, or allof the features described herein. Thus, an embodiment may have apositionable inlet wherein the inlet makes an obtuse angle with respectto the collection tube. This may be combined with a wetting portcomprising an air injector with an interior and a liquid injector;wherein an end of the liquid injector is inserted into the interior ofthe air injector.

FIG. 9A and FIG. 9B show another embodiment for an air inlet 906 coupledthrough an aperture 926 to the interior of a cyclone body 902. Aflexible diaphragm 940 is attached at a top to the interior wall of airinlet 906 and is attached at a bottom to the cyclone body. Air flowsthrough opening 926 through the interior of the cyclone body 902 outthrough blower 920. In this embodiment, the air inlet 906 is movablerelative to the cyclone body along the axis of the cyclone. In oneposition of air inlet 906, a wide opening 926 is provided, but inanother position of air inlet 906, the diaphragm 940 deforms to providea much narrower opening 926. A narrow opening will, for the same flowrate, cause air to flow through the opening 926 at a higher velocity,resulting in discrimination of smaller particles. Note that thisembodiment can be combined with embodiments described above to provide acyclone with a plurality of features described herein. Note also, thatthe aperture formed by the diaphragm makes a smooth transition from theair inlet to the collection tube. Note further that in some embodimentsthe opening 926 is varied by inflating or deflating an inflatablediaphragm 940.

FIG. 10A and FIG. 10B show an alternative embodiment wherein the airinlet 1006 moves laterally with respect to the cyclone body 1002, ratherthan longitudinally as shown in FIGS. 9A and 9B. The flexible diaphragm1040 is attached to the air inlet 1006 interior wall and to the cyclonebody 1002. In one position, the aperture 1026 of the diaphragm 1040 isopened to a maximum extent (FIG. 10A). In another position—laterally,with respect to cyclone body 1002—the aperture 1026 is narrowed (FIG.10B). Note that in FIGS. 9 and 10, the diaphragm produces an interiorwall that is smooth for a smooth transition between the two parts,thereby avoiding the generation of turbulence at the aperture andreducing settlement of particulates at or near the aperture. FIG. 10Cshows yet another alternative for providing a smooth transition acrossthe aperture. In this embodiment, flexible diaphragm 1040 is deformableby way of air provided by an air pump (not shown). Thus, aperture 1026can be made small or large without movement of any parts other than thediaphragm 1040. By variably inflating the diaphragm, one can obtain goodcontrol over the size of the aperture 1026.

Thus, some embodiments have a flexible diaphragm to couple air from theair inlet to the collection tube. One embodiment is an air flow devicewith a collection tube providing a collection path. Coupled to thecollection tube, is an air inlet to receive air from the exterior of thedevice and to transmit air to the interior of the collection tube. Aflexible diaphragm attached at one side to an interior wall of the airinlet and attached at another side to the collection tube forms asmoothly transitioning aperture. In one embodiment, the flexiblediaphragm is inflatable to vary the size of an aperture formed by thediaphragm. In another embodiment, the air inlet moves with respect tothe collection tube to flex the diaphragm to vary the size of anaperture formed by the diaphragm. The air inlet may move laterally withrespect to the collection tube in one embodiment or may movelongitudinally with respect to the collection tube in anotherembodiment. In some embodiments, the diaphragm attaches to a collectioninsert of the collection tube.

FIG. 11A and FIG. 11B show yet another way to controllably restrict theaperture between the air inlet 1106 and cyclone body 1102 by changingthe size of the aperture 1126. The size of the aperture 1126 is variedby a small rotation of collection insert 1114. This embodiment may becombined with a diaphragm to smooth the transition across aperture 1126.By a small rotation of the collection insert, particles of differentsizes can be collected. Thus, in some embodiments, an aperture betweenthe air inlet and the collection tube may be varied in size by arelatively small rotation of a collection insert inserted into thecollection tube interior.

FIG. 12A and FIG. 12B show a cyclone with multiple air inlets 1206,1256, and 1266. Each air inlet is connected by an aperture in collectioninsert 1214 to the interior of the cyclone body 1202. Each aperture incollection insert 1214 may line up with an air inlet. The apertures maybe so arranged that only one inlet is open at a time, or so that aplurality of inlets are open at a time as shown in FIG. 12A. Thus, theatmosphere can be collected through different inlets, each with its ownair flow rate. The air flow rate may be determined by the size of theaperture. This means that different particles sizes can be collected.FIG. 12B shows that air inlets may be placed at different positionsalong the length of the collection tube 1202. In FIG. 12B, two airinlets 1206 and 1266 are equally displaced along the length ofcollection tube 1202. A third air inlet 1256 is displaced further alongthe length of collection tube 1202. Thus, in some embodiments, aplurality of air inlets may be disposed angularly about thecircumference of the collection tube, or disposed along the length ofthe collection tube, or both. This enables collection of different sizeparticles at different areas along the length of the collection tube. Insome embodiments, one or more air inlets may be selected by rotating thecollection insert 1214 or translating the collection insert 1214 or by acombination of rotation and translation. A further advantage of usingmultiple air inlets simultaneously is that larger volumes of air can besampled for particulates.

Thus, some embodiments comprise a collection tube with a plurality ofair inlets to receive air from the exterior of the device and totransmit air to the interior of the collection tube. An embodiment mayfurther comprise a collection insert with apertures that may align withone or more air inlets at a time. In one embodiment, some air inlets aredisplaced from each other longitudinally along the length of thecollection tube. In another embodiment, or in the same embodiment, someair inlets are displaced angularly from each other about thecircumference of the collection tube. Moreover, in some embodiments,some air inlets are connected to the collection tube through aperturesof different sizes.

FIG. 13 shows a functional block diagram for automatically adjusting thesize of an inlet or adjusting the speed of a blower motor in response toa detected particle size. Detector 1308 is positioned as shown in anyone of FIG. 2, 4, 5 or 8 or otherwise positioned in a path to receiveand detect particles. Detector 1308 can detect the size of particles itreceives or that pass through or by it. In one embodiment, detector 1308comprises a laser light that is deflected by particles. The bigger theparticle causing the deflection, the signal seen by the detectorindicates the specific target particle size. Thus, detector 1308 isresponsive to particle size. Further, detector 1308 produces a signalresponsive to particle size.

A controller 1306 receives a signal from detector 1308 that isresponsive to particle size. controller 1306 is programmed to produce asignal responsive to the signal from detector 1308 that drives a primemover, such as a stepper motor, 1304. Generally, prime mover 1304 is anelectromechanical device that transfers an electrical signal to motion.Device 1304 drives a movable part of the collection/detection apparatusto vary the size of an inlet through which the particles pass. Inaddition, or in the alternative, controller 1306 adjusts the speed of ablower motor 1310 that causes a change in the air flow rate through theapparatus. The change in air flow rate allows for adjustment in particlesize collection.

In one embodiment, controller 1306 comprises a look up table or othermethod to develop an output signal to drive motor 1304 in response to aninput signal responsive to particle size. Motor 1304 drives a movingpart of the apparatus to vary the size of an inlet through which theparticles pass. For example, referring to FIG. 2, the motor could drivethe collection insert 314 either translationally in one embodiment orrotationally in another embodiment to very the size of the inlet throughwhich the particles pass. As another example, referring to FIG. 9 or 10,the air inlet 906 or 1006 can be moved translationally to vary the sizeof the inlet. In the embodiment of FIG. 11, as yet another example, thecollection insert 1114 can be rotated to vary inlet size.

Thus, in response to a particle stream flowing through detector 1308,the detector outputs a signal responsive to and indicative of the sizeof particles detected. The controller receives this signal and, inresponse, outputs a signal to either the prime mover 1304 or the blowermotor 1310 or both. The signal output of the microcontroller may becalculated or calibrated to cause air to pass through an inlet of a sizeselected to optimize collection of particles of a particular size. Forexample, if the detector detects a particle size of 10 microns, thesystem may be calibrated to create an air inlet that increases thecollection of particles of this size. This may be done automatically.Generally, the smaller the opening of the inlet, the higher the velocityof air flow there through, and the smaller the particles beingcollected. Conversely, a larger opening reduces velocity resulting inlarger particles being collected.

FIG. 14 shows another aspect of some embodiments which have a cap 1402over the air inlet 1406 of the apparatus. In some embodiments, the cap1402 is movable with respect to inlet 1406. Thus, in FIG. 14A the cap israised so that height a is tall. In FIG. 14B the cap is lowered. Whenthe cap is raised, velocity into the inlet decreases and largerparticles are collected. Conversely, when the cap is lowered, velocityincreases and smaller particles are collected. In some embodiments, awidth of the cap may be varied to adjustably select particle size. Thiscan be seen by comparing b of FIGS. 14B and 14C. In some embodiments,therefore, the cap or the inlet may be moved or adjusted with respect tothe other to change the volume between the cap and the inlet toadjustably select particle size. In some embodiments, the cap isadjustable by prime mover 1304 which is ultimately responsive to thesignal from the detector indicative of particle size. In someembodiments, the cap or the inlet is adjustable by rotating the cap orinlet to vary the velocity of particles being aspirated into the inlet.Note finally, that in some embodiments the detector is in a pathseparate from the collection tube. In some embodiments, the detectionpath may be within the collection tube.

The present invention and some of its advantages have been described indetail for some embodiments. It should be understood that variouschanges, substitutions and alterations can be made herein withoutdeparting from the spirit and scope of the invention as defined by theappended claims. An embodiment of the invention may achieve multipleobjectives, but not every embodiment falling within the scope of theattached claims will achieve every objective. Moreover, the scope of thepresent application is not intended to be limited to the particularembodiments of the process, machine, manufacture, composition of matter,means, methods and steps described in the specification. One of ordinaryskill in the art will readily appreciate from the disclosure of thepresent invention that processes, machines, manufacture, compositions ofmatter, means, methods, or steps, presently existing or later to bedeveloped are equivalent to, and fall within the scope of, what isclaimed. Accordingly, the appended claims are intended to include withintheir scope such processes, machines, manufacture, compositions ofmatter, means, methods, or steps.

1. An air tester for testing for the presence of biological, explosive,chemical or nuclear particulates in the air, comprising: a collectiontube; an air inlet to receive air and to channel the air through a firstopening in a wall of the collection tube; and a removable insertinsertable into the collection tube and having interior walls, theremovable insert collecting liquid and particulates on the interiorwalls of the insert; the removable insert being positionable to align afirst opening in a wall of the insert with the first opening in a wallof the collection tube to allow air to pass through the alignedopenings, the removable insert being substantially concentric with thecollection tube; a wall of the collection tube having a second openingto a detection path; a wall of the insert having a third opening that,in a detection mode aligns with the second opening in the wall of thecollection tube when the first opening in the wall of the collectiontube is aligned with the first opening in the wall of the insert, toallow air to pass through the insert to the detection path.
 2. The airtester of claim 1, further comprising: in a wall of the insert, a thirdopening that can, in a collection mode, align with the first opening inthe wall of the collection tube when the second openings are notaligned, to allow air to pass into and through the collection tube whileair is sealed off to the detection path.
 3. The air tester of claim 2,wherein the insert rotates to a first position of alignment for thecollection mode and rotates into a second position of alignment for thedetection mode.
 4. The tester of claim 1, wherein the alignment betweenthe first opening in the wall of the collection tube and the firstopening in the wall of the insert is electro-mechanically adjustable inresponse to a signal from a detector in the detection path.
 5. Thetester of claim 4, wherein the signal from the detector is a function ofa size of particles detected by the detector.
 6. The tester of claim 1,wherein a path of the air inlet is at an obtuse angle to a main axis ofthe collection tube.
 7. The tester of claim 1, further comprising awetting port comprising an air injector with an interior and a liquidinjector; wherein an end of the liquid injector is inserted into theinterior of the air injector.
 8. A switchable air flow device for use ina detector/collector of biological, explosive, chemical or nuclearparticulates in the air, the switchable air flow device comprising: acollection tube providing a first path for air to flow; an air inletconnecting to the collection tube; a detection path providing a secondpath for air to flow; and an insert positionable within the collectiontube, with openings therein, to allow air to flow from the air inletthrough the insert to the detection path when the insert is rotated tobe in a first position and to allow air to flow from the air inlet tothe collection tube while blocking the detection path when the insert isrotated to be in a second position, the insert comprising a vortexfinder.
 9. The device of claim 8, wherein the insert is removable fromthe collection tube.
 10. The device of claim 8, wherein a path of theair inlet is at an obtuse angle to a main axis of the collection tube.11. The device of claim 8, wherein the insert is positionable from thefirst position to the second position by rotation of the insert.
 12. Thedevice of claim 8, wherein the insert has a heating layer.
 13. Thedevice of claim 12, wherein the insert has an insulation layer outsidethe heating layer.
 14. The device of claim 8, wherein the secondposition is determined in response to a signal from a detector in thedetection path.
 15. The device of claim 8, further comprising anadjustable cap over an end of the air inlet to vary the flow rate of airin the inlet.
 16. An air flow device for use in a collector ofbiological, explosive, chemical or nuclear particulates in the air, theair flow device comprising: a collection tube having an interior and afirst aperture, the collection tube providing a collection path; coupledto the collection tube, an air inlet to receive air from an exterior ofthe device and to transmit air to the interior of the collection tube,the collection tube being cylindrical and rotatable about a longitudinalaxis to align the first aperture in the collection tube with the airinlet a detection path having an aperture align-able with a secondaperture of the collection tube to enable air to pass through the secondcollection tube aperture and the detection path aperture into thedetection path.
 17. The device of claim 16, wherein a flow rate throughat least one the inlet is adjustable.
 18. A particle detection andcollection device, comprising: a collection path and a detection path,the collection path bypassing the detection path and the detection pathbypassing the collection path; a detector in the detection path todetect particles and to produce a signal responsive to particle size;and circuitry to produce a signal to an electromechanical device tocause motion to vary the velocity of air flowing through an inlet to thecollection path in response to the signal from the detector; anelectromechanical device to vary a position of a moveable part of thedevice to vary the velocity of air flowing through the inlet in responseto the signal from the detector.
 19. The device of claim 18, wherein themoveable part is a collection insert inserted into the collection path.20. The device of claim 18, further comprising a cap over an end of theinlet, wherein adjusting a relative position between the cap and theinlet adjusts a velocity of air received by the inlet.